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  <Canvas.Triggers>
    <EventTrigger RoutedEvent="Canvas.Loaded">
      <EventTrigger.Actions>
        <TriggerActionCollection>
          <BeginStoryboard>
            <Storyboard BeginTime="0" Duration="Forever">
              <DoubleAnimation Storyboard.TargetName="path1" Storyboard.TargetProperty="(Canvas.Top)" From="0" To="300" AutoReverse="true" BeginTime="0:0:0" Duration="0:0:2" RepeatBehavior="Forever"/>
              <DoubleAnimation Storyboard.TargetName="path2" Storyboard.TargetProperty="(Canvas.Left)" From="0" To="400" AutoReverse="true" BeginTime="0:0:0" Duration="0:0:4" RepeatBehavior="Forever"/>
              <DoubleAnimation Storyboard.TargetName="path3" Storyboard.TargetProperty="(Canvas.Top)" From="0" To="200" AutoReverse="true" BeginTime="0:0:0" Duration="0:0:8" RepeatBehavior="Forever"/>
              <DoubleAnimation Storyboard.TargetName="path3" Storyboard.TargetProperty="(Canvas.Left)" From="0" To="350" AutoReverse="true" BeginTime="0:0:0" Duration="0:0:4" RepeatBehavior="Forever"/>
              <DoubleAnimation Storyboard.TargetName="path4" Storyboard.TargetProperty="(Canvas.Top)" From="0" To="250" AutoReverse="true" BeginTime="0:0:0" Duration="0:0:2" RepeatBehavior="Forever"/>
              <DoubleAnimation Storyboard.TargetName="path4" Storyboard.TargetProperty="(Canvas.Left)" From="0" To="30" AutoReverse="true" BeginTime="0:0:0" Duration="0:0:2" RepeatBehavior="Forever"/>
              <DoubleAnimation Storyboard.TargetName="path5" Storyboard.TargetProperty="(Canvas.Top)" From="0" To="278" AutoReverse="true" BeginTime="0:0:0" Duration="0:0:4" RepeatBehavior="Forever"/>
              <DoubleAnimation Storyboard.TargetName="path6" Storyboard.TargetProperty="(Canvas.Left)" From="0" To="176" AutoReverse="true" BeginTime="0:0:0" Duration="0:0:4" RepeatBehavior="Forever"/>
            </Storyboard>
          </BeginStoryboard>
        </TriggerActionCollection>
      </EventTrigger.Actions>
    </EventTrigger>
  </Canvas.Triggers>

  <Rectangle x:Name="path1" Opacity=".65" Fill="orange" Height="100" Width="100" RadiusX="10" RadiusY="10" />
  <Rectangle x:Name="path2" Opacity=".65" Fill="blue" Height="100" Width="100" RadiusX="10" RadiusY="10" />
  <Rectangle x:Name="path3" Opacity=".65" Fill="red" Height="100" Width="100" RadiusX="10" RadiusY="10" />
  <Rectangle x:Name="path4" Opacity=".65" Fill="yellow" Height="100" Width="100" RadiusX="10" RadiusY="10" />
  <Rectangle x:Name="path5" Opacity=".65" Fill="green" Height="100" Width="100" RadiusX="10" RadiusY="10" />

  <Rectangle x:Name="path6" Opacity=".65" Height="100" Width="100" RadiusX="10" RadiusY="10">
    <Rectangle.Fill>
      <LinearGradientBrush StartPoint="0,0.5" EndPoint="1,0.5">
        <LinearGradientBrush.GradientStops>
          <GradientStop  Offset="0"  Color="white"/>
          <GradientStop Offset="1" Color="Gray"/>
        </LinearGradientBrush.GradientStops>
      </LinearGradientBrush>
    </Rectangle.Fill>
  </Rectangle>
  </Canvas>